US6014006A - Induction motor control system with speed and flux estimation - Google Patents

Induction motor control system with speed and flux estimation Download PDF

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US6014006A
US6014006A US09/339,485 US33948599A US6014006A US 6014006 A US6014006 A US 6014006A US 33948599 A US33948599 A US 33948599A US 6014006 A US6014006 A US 6014006A
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stator
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Ross Maxwell Stuntz
Vladimir Aleksandrovich Bondarko
Alexander Timofeevich Zaremba
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Ford Global Technologies LLC
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/13—Observer control, e.g. using Luenberger observers or Kalman filters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/14—Estimation or adaptation of machine parameters, e.g. flux, current or voltage
    • H02P21/141—Flux estimation
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/14—Estimation or adaptation of machine parameters, e.g. flux, current or voltage
    • H02P21/18—Estimation of position or speed

Definitions

  • the present invention relates to control systems for induction motors.
  • the spatial saliencies tracking methods require injection of the separate high frequency carrier signal and work best at low speed. They are based on the accurate analysis of machine physical structure irregularities and have intrinsic limitations originating from the requirements of separation of fundamental and carrier frequencies and detection of low amplitude spatial information signal.
  • the control methods from the second group rely on different control techniques.
  • One of the approaches is based on augmentation of the plant to include dynamics of unknown parameters and use of state dependent Riccati equation filter methodology.
  • a particular control method employs two complementary speed and flux observers or estimators.
  • the main high gain speed and flux estimator works in the motoring and generating region and requires the knowledge of motor speed sign.
  • the auxiliary estimator operates in generating and braking modes but can be justified if motor speed varies sufficiently slowly. However, the switching between the two estimators can cause divergence when the induction motor is operated at low speed under large load.
  • the high gain estimator is utilized in a reference frame related with a flux estimation vector. Rigorous closed loop analysis taking into account rotor resistance variation, and error in estimation of rotor flux and speed provides conditions under which asymptotic torque tracking is achieved.
  • An object of the present invention is to provide method and apparatus for controlling an induction motor using pseudo (filtered) electrical current and voltage signals and observable time derivatives thereof as inputs to a system of linear algebraic equations representing motor dynamics.
  • the present invention provides method and apparatus for controlling an induction motor wherein a system of linear algebraic equations is developed to define a speed observer or estimator based on motor dynamics.
  • the speed observer equations have rotor speed as the only unknown variable and have pseudo (filtered) electrical current and voltage signals and observable derivatives thereof as inputs.
  • Rotor speed is estimated as a rational function of the measured and observable variable stator current and voltage inputs.
  • Rotor flux then is estimated directly from rotor speed using an induction motor equation.
  • Rotor flux angle is determined from rotor flux for use in controlling torque of the induction motor.
  • FIG. 1 is a schematic view of an induction motor and control system pursuant to an embodiment of the invention.
  • FIG. 1 a block diagram of a motor control system in accordance with an embodiment of the present invention is illustrated.
  • an induction motor 10 is shown driven by a pulse width modulating (PWM) voltage source inverter 12, a field oriented controller 14, synchronous-to-stationary frame transformation block 16, two to three phase transformation block 17, a stator current observer 22, stator voltage observer 24, three to two phase transformation block 26, a speed observer or estimator 30, and a flux observer 32 providing estimated flux values to rotor flux calculator 34.
  • PWM pulse width modulating
  • Polyphase current rotating in the same direction as, but faster than, the rotor 10a of the induction motor 10 will create a torque in a direction so as to aid in rotor rotation.
  • net electrical power flow is into the motor electrical terminals, and the motor 10 is considered to be in a "motoring" mode.
  • polyphase currents rotating slower than the motor create a torque in a direction opposing the rotor rotation. Net electrical power flow is thus out of the motor electrical terminals, and the motor 10 is considered to be in a "generating" mode.
  • Controller 14 sends stator voltage commands u d and u q (d, q reference frame) to transform blocks 16, 17 which rotate the voltage commands from the synchronous to the stationary frames and, in turn, send transformed commands u a , u b , u c to inverter 12 for control of the motor 10.
  • Stator current observer 22 receives measured current signals from current sensors 18 and transform block 26, which rotates the measured current signals i sa , i sb , and i sc from the three phase frame to two phase frame to provide measured stator currents i sx and i sy to the current observer 22.
  • the current observer 22 generates pseudo currents i s0 , i s1 , i s2 as described below and sends them to speed observer or estimator 30.
  • the voltage observer 24 receives commanded stator voltage signals u x and u y calculated in the stationary frame and generates pseudo voltage signals u 0 and u 1 (as described below) and sends them to speed observer or estimator 30.
  • the speed observer 30 estimates the rotational electrical speed of rotor 10a by processing a system of algebraic equations to be described below using the pseudo stator current signals i s0 , i s1 , i s2 and pseudo stator voltage signals u 0 , u 1 as inputs to the equations.
  • the estimated rotor speed, ⁇ r is sent to the flux observer 32 which estimates the rotor flux, ⁇ r , directly from rotor speed using an induction motor equation described below.
  • the rotor flux is estimated directly from the rotor speed and stator current signals.
  • the estimated rotor flux is used by the rotor flux angle calculator 34 to calculate the rotor flux angle ⁇ r .
  • the rotor flux angle is used with the torque command, T e *, and rotor flux command, ⁇ r *, and measured stator currents i sx , i sy to control induction motor 10 via conventional techniques such as indirect field orientation methods incorporating slip frequency calculator and current regulator.
  • Current observer 22, voltage observer 24, speed observer 30, flux observer 32, and flux angle calculator 34 are embodied in a microprocessing system of a motor control unit.
  • the estimated rotor flux angle, ⁇ r is sent to transform block 16 for purposes of transforming voltage control signal from a synchronous frame to stator stationary frame.
  • a dynamic model of a three phase induction machine 10, in a conventional stationary stator reference frame (x, y) is as follows: ##EQU1##
  • ⁇ and ⁇ are the angular position and mechanical speed of the rotor 10a, ⁇ r , u s are rotor flux, stator current and voltage in the stator frame of reference (x, y), respectively.
  • ⁇ r T is a transposed vector for ⁇ r .
  • R r , R s are rotor and stator resistances
  • M is a mutual inductance
  • Lr M+L 1r
  • L s M+L 1s are rotor and stator inductances
  • ⁇ 1-M 2 /L s
  • L r is the leakage parameter
  • m is the moment of inertia of the motor
  • n p is the number of pole pairs
  • T L is an external load torque.
  • T e *, ⁇ r * are reference (commanded) values of torque and rotor flux.
  • Integrating electrical frequency signal ⁇ e * (5) provides information about orientation of rotor flux which allows separation of the problems of flux control and reference torque tracking.
  • An object of the invention is to design the speed observer 30 for speed estimation and the flux observer 32 for flux estimation using only information about stator current signals i sx , i sy and stator voltage signals u x , u y .
  • the speed observer design assumes that all motor parameters have constant known values. To further simplify the problem, the rotor speed ⁇ is assumed to be constant, but unknown. The second assumption can be justified by the fact that actual rotor speed varies slowly as compared to rotor flux and stator current. Rotor speed changes can be neglected in design of the speed observer 30.
  • the speed observer 30 may be briefly described as follows:
  • rotor velocity is the only unknown variable of the equations, it may be calculated as a rational function of filtered current, voltage and their observable derivatives.
  • Equation (10) can be represented in the form:
  • Equation (11) contains derivatives of current and voltage signals and can not be used directly to determine rotor speed.
  • Equation (14) contains derivatives of current and voltage signals and can not be used directly to determine rotor speed.
  • low pass filtered versions of stator current and stator voltage are introduced by current observer 22 and voltage observer 24 as pseudo current i s0 and voltage u 0 as follows ##EQU8## where G>0 and G is the filter gain. Equation (15) provides pseudo (filtered) current and voltage i s0 and u 0 from measured stator current i s and stator voltage u.
  • Equations (21)-(25) define the speed observer 30.
  • the speed is obtained as a solution (21) of the system of algebraic equation with pseudo (filtered) current and voltage signals i s0 , i s1 , i s2 and u 0 , u 1 as inputs.
  • the estimated rotor speed, ⁇ r is sent to the flux observer 32 which estimates the rotor flux, ⁇ r , using equation (3) rewritten as: ##EQU13## is an exponentially stable matrix.
  • the flux estimation signal ⁇ r is bounded for any bounded input i s .
  • the estimated rotor flux is used by the rotor flux angle calculator 34 to calculate the rotor flux angle, ⁇ r , using the equation: ##EQU14## where ⁇ rx and ⁇ ry are rotor flux with respect to stator reference frame (x, y).
  • the rotor flux angle is used with the torque command, T e *, and rotor flux command, ⁇ r *, and measured current signals i sx , i sy to control induction motor 10 via conventional techniques such as indirect field orientation methods incorporating slip frequency calculator and current regulator.
  • a speed estimation is obtained as a solution of a continuous set of equations (20) over given time interval.
  • the usual strategy is to put maximum weight on recent measurements and gradually discount previous measurements.
  • i d and i q are stator currents in the respective d and q stator references frames and ⁇ d is flux in the (d, q) stator reference frame and ⁇ r t is the transpose of ⁇ r .

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Ac Motors In General (AREA)

Abstract

Method of controlling torque of a multi-phase induction motor (10) includes estimating rotor speed as a rational function of filtered stator current is0 and voltage u0 and first and second order derivatives of the filtered stator current and first order derivative of the filtered stator voltage, estimating rotor flux from said estimated rotor speed, estimating rotor flux angle from said estimated rotor flux, and using the estimated rotor flux angle to control motor torque.

Description

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to control systems for induction motors.
2. Description of Related Art
In recent years, there has been substantial research on advanced control systems for controlling induction motors without rotational transducers to achieve high dynamic performance of induction motor drives. A major element of these control systems has been the estimation of the rotor position or the position of the rotor flux without using a rotor position sensor. The techniques used for these purposes can be divided into two groups: a) tracking machine spatial saliencies and b) using a variety of control methods for speed and flux estimation.
The spatial saliencies tracking methods require injection of the separate high frequency carrier signal and work best at low speed. They are based on the accurate analysis of machine physical structure irregularities and have intrinsic limitations originating from the requirements of separation of fundamental and carrier frequencies and detection of low amplitude spatial information signal.
The control methods from the second group rely on different control techniques. One of the approaches is based on augmentation of the plant to include dynamics of unknown parameters and use of state dependent Riccati equation filter methodology. A particular control method employs two complementary speed and flux observers or estimators. The main high gain speed and flux estimator works in the motoring and generating region and requires the knowledge of motor speed sign. The auxiliary estimator operates in generating and braking modes but can be justified if motor speed varies sufficiently slowly. However, the switching between the two estimators can cause divergence when the induction motor is operated at low speed under large load. The high gain estimator is utilized in a reference frame related with a flux estimation vector. Rigorous closed loop analysis taking into account rotor resistance variation, and error in estimation of rotor flux and speed provides conditions under which asymptotic torque tracking is achieved.
An object of the present invention is to provide method and apparatus for controlling an induction motor using pseudo (filtered) electrical current and voltage signals and observable time derivatives thereof as inputs to a system of linear algebraic equations representing motor dynamics.
SUMMARY OF THE INVENTION
The present invention provides method and apparatus for controlling an induction motor wherein a system of linear algebraic equations is developed to define a speed observer or estimator based on motor dynamics. The speed observer equations have rotor speed as the only unknown variable and have pseudo (filtered) electrical current and voltage signals and observable derivatives thereof as inputs. Rotor speed is estimated as a rational function of the measured and observable variable stator current and voltage inputs. Rotor flux then is estimated directly from rotor speed using an induction motor equation. Rotor flux angle is determined from rotor flux for use in controlling torque of the induction motor.
BRIEF DESCRIPTION OF THE DRAWINGS
The sole FIG. 1 is a schematic view of an induction motor and control system pursuant to an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the FIGURE, a block diagram of a motor control system in accordance with an embodiment of the present invention is illustrated. In particular, an induction motor 10 is shown driven by a pulse width modulating (PWM) voltage source inverter 12, a field oriented controller 14, synchronous-to-stationary frame transformation block 16, two to three phase transformation block 17, a stator current observer 22, stator voltage observer 24, three to two phase transformation block 26, a speed observer or estimator 30, and a flux observer 32 providing estimated flux values to rotor flux calculator 34.
Polyphase current rotating in the same direction as, but faster than, the rotor 10a of the induction motor 10 will create a torque in a direction so as to aid in rotor rotation. In this operational mode, net electrical power flow is into the motor electrical terminals, and the motor 10 is considered to be in a "motoring" mode. Conversely, polyphase currents rotating slower than the motor create a torque in a direction opposing the rotor rotation. Net electrical power flow is thus out of the motor electrical terminals, and the motor 10 is considered to be in a "generating" mode.
Controller 14 sends stator voltage commands ud and uq (d, q reference frame) to transform blocks 16, 17 which rotate the voltage commands from the synchronous to the stationary frames and, in turn, send transformed commands ua, ub, uc to inverter 12 for control of the motor 10. Stator current observer 22 receives measured current signals from current sensors 18 and transform block 26, which rotates the measured current signals isa, isb, and isc from the three phase frame to two phase frame to provide measured stator currents isx and isy to the current observer 22. The current observer 22 generates pseudo currents is0, is1, is2 as described below and sends them to speed observer or estimator 30.
The voltage observer 24 receives commanded stator voltage signals ux and uy calculated in the stationary frame and generates pseudo voltage signals u0 and u1 (as described below) and sends them to speed observer or estimator 30.
The speed observer 30 estimates the rotational electrical speed of rotor 10a by processing a system of algebraic equations to be described below using the pseudo stator current signals is0, is1, is2 and pseudo stator voltage signals u0, u1 as inputs to the equations.
The estimated rotor speed, ωr is sent to the flux observer 32 which estimates the rotor flux, λr, directly from rotor speed using an induction motor equation described below. The rotor flux is estimated directly from the rotor speed and stator current signals. The estimated rotor flux is used by the rotor flux angle calculator 34 to calculate the rotor flux angle Θr. The rotor flux angle is used with the torque command, Te *, and rotor flux command, λr *, and measured stator currents isx, isy to control induction motor 10 via conventional techniques such as indirect field orientation methods incorporating slip frequency calculator and current regulator. Current observer 22, voltage observer 24, speed observer 30, flux observer 32, and flux angle calculator 34 are embodied in a microprocessing system of a motor control unit.
The estimated rotor flux angle, Θr, is sent to transform block 16 for purposes of transforming voltage control signal from a synchronous frame to stator stationary frame.
A dynamic model of a three phase induction machine 10, in a conventional stationary stator reference frame (x, y) is as follows: ##EQU1##
Here the variables Θ and ω are the angular position and mechanical speed of the rotor 10a, λr, us are rotor flux, stator current and voltage in the stator frame of reference (x, y), respectively. λr T is a transposed vector for λr.
The parameters Rr, Rs are rotor and stator resistances, M is a mutual inductance, Lr=M+L1r, Ls =M+L1s are rotor and stator inductances, σ=1-M2 /Ls Lr is the leakage parameter, m is the moment of inertia of the motor, np is the number of pole pairs, and TL is an external load torque.
For vector control of induction motor 10, it is required to measure or estimate rotor mechanical speed ω. Then the necessary stator frequency command ωs * can be obtained by summing the commanded slip frequency ωs * with the measured rotor speed ω:
ω.sub.e *=n.sub.p ω+ω.sub.s *            (5)
where ##EQU2## and Te *, λr * are reference (commanded) values of torque and rotor flux.
Integrating electrical frequency signal ωe * (5) provides information about orientation of rotor flux which allows separation of the problems of flux control and reference torque tracking. An object of the invention is to design the speed observer 30 for speed estimation and the flux observer 32 for flux estimation using only information about stator current signals isx, isy and stator voltage signals ux, uy.
The speed observer design assumes that all motor parameters have constant known values. To further simplify the problem, the rotor speed ω is assumed to be constant, but unknown. The second assumption can be justified by the fact that actual rotor speed varies slowly as compared to rotor flux and stator current. Rotor speed changes can be neglected in design of the speed observer 30.
The speed observer 30 may be briefly described as follows:
Due to assumption ω≈constant, the last two equations of the dynamic model (3), (4) are sufficient to describe the dynamics of induction motor 10.
These equations (3), (4) are linear and allow elimination of unobservable flux and obtainment of a differential equation having stator current and voltage signals only.
The same equations (3), (4) are valid for filtered versions of current and voltage, whose derivatives are observable.
Since rotor velocity is the only unknown variable of the equations, it may be calculated as a rational function of filtered current, voltage and their observable derivatives.
Having estimated rotor speed, we can evaluate flux directly from equation (3).
The speed observer 30 embodies equations (3), (4) rewritten as follows: ##EQU3## where is =(isx, isy), u=(ux, uy), ωr is rotor electrical speed and ωr =np ω, u is stator voltage, ##EQU4##
Differentiating equation (7) and eliminating i, by using equation (8) we get: ##EQU5## Equation (10) can be represented in the form:
a+Jb·ω.sub.r =0                             (11)
where a and b are 2-vectors as follows: ##EQU6## Thus, we get an overdetermined linear algebraic system (11) with respect to ωr. Minimizing mean square residual |a+Jbωr |2 gives an estimation of the rotor speed: ##EQU7## where bt represents the transpose of the vector b. Equation (14) contains derivatives of current and voltage signals and can not be used directly to determine rotor speed. To resolve this problem, low pass filtered versions of stator current and stator voltage are introduced by current observer 22 and voltage observer 24 as pseudo current is0 and voltage u0 as follows ##EQU8## where G>0 and G is the filter gain. Equation (15) provides pseudo (filtered) current and voltage is0 and u0 from measured stator current is and stator voltage u.
Substituting (15) into (11) gives ##EQU9## This means that:
a.sub.G +Jb.sub.G ·=ε                     (19)
where ε is a small number and ε→0 exponentially as t (time)→∞; or, roughly speaking, we can use for speed estimation the following equation:
a.sub.G +Jb.sub.G ·ω.sub.r =0.              (20)
Therefore, we get: ##EQU10## Observable first and second order derivatives of pseudo (filtered) current is0 and first order derivative of pseudo (filtered) voltage u0 are:
i.sub.s1 =di.sub.s0 |dt, i.sub.s2 =d.sup.2 i.sub.s0 |dt.sup.2, u.sub.1 =du.sub.0 |dt        (24)
can be determined as a solution of equations: ##EQU11## The last equality in (25) follows from: ##EQU12##
Equations (21)-(25) define the speed observer 30. The speed is obtained as a solution (21) of the system of algebraic equation with pseudo (filtered) current and voltage signals is0, is1, is2 and u0, u1 as inputs.
The estimated rotor speed, ωr, is sent to the flux observer 32 which estimates the rotor flux, λr, using equation (3) rewritten as: ##EQU13## is an exponentially stable matrix. The flux estimation signal λr is bounded for any bounded input is.
The estimated rotor flux is used by the rotor flux angle calculator 34 to calculate the rotor flux angle, Θr, using the equation: ##EQU14## where λrx and λry are rotor flux with respect to stator reference frame (x, y).
The rotor flux angle is used with the torque command, Te *, and rotor flux command, λr *, and measured current signals isx, isy to control induction motor 10 via conventional techniques such as indirect field orientation methods incorporating slip frequency calculator and current regulator.
Speed Observer Optimized To Noise
To improve speed observer robustness with respect to noise in stator current measurements, a speed estimation is obtained as a solution of a continuous set of equations (20) over given time interval. The usual strategy is to put maximum weight on recent measurements and gradually discount previous measurements. Minimizing integral mean error: ##EQU15## where t is the time moment, s is a dummy variable of integration, and discount factor e-gs is selected as an exponential function, and leading to the following formulae: ##EQU16## where bG ' is defined by equations (23)-(25), z,900 and Φ are the filtered versions of ζ, φ, respectively, and g is the filter gain.
By comparing (30)-(34) with (21), it can be concluded that the speed observer 30 obtained from minimization of (29) contains additional filtering (32), (33) of the denominator and numerator of expression (21).
Analysis of singular point
Considering the situation when b=0 and consequently a=0 in equation (11) provides a singular case at which induction motor speed can not be determined from system (11).
The motor dynamics for b=0 are governed by the equation ##EQU17##
Substituting equation (35) into equation (7) we get:
ηMi.sub.s -Aλ.sub.r =0                          (36)
From (36) it follows that at the singular point, the current and flux are related by algebraic equality. Transforming (36) to the (d, q) stator reference frame related with rotor flux, we get two equivalent equations:
Mi.sub.d =λ.sub.d                                   (37)
ηMi.sub.q +ω.sub.r λ.sub.d =0             (38)
where ##EQU18## where id and iq are stator currents in the respective d and q stator references frames and λd is flux in the (d, q) stator reference frame and λr t is the transpose of λr.
Comparing the equation (38) with (5), we find in the singular case that the electrical excitation frequency ωe equals zero:
ω.sub.e =0.                                          (39)
This corresponds to the special situation when the electrical field is not rotating and machine slip, s: ##EQU19## is infinite.
In the vicinity of the observer singular point, an additional speed observer (not shown) may be used if desired or needed and based on dynamic equations: ##EQU20## where
b=-i.sub.s1 +(βηM-γ)i.sub.s +δu.      (42)
From equations (41) and (8), the following formulae are generated: ##EQU21## which define flux and speed changes in the area where ωe ≅0.
While the invention is described above in terms of specific embodiments thereof, it is not intended to be limited thereto but rather only to the extent set forth hereafter in the following claims.

Claims (10)

What is claimed is:
1. A method of controlling torque of a multi-phase induction motor, comprising:
(a) estimating rotor speed as a function of filtered stator current and voltage signals and first and second order derivatives of the filtered stator current signal and first order derivative of the filtered stator voltage signal,
(b) estimating rotor flux from said estimated rotor speed,
(c) estimating rotor flux angle from said estimated rotor flux, and
(d) using the estimated rotor flux angle to control motor torque.
2. The method of claim 1 wherein said current signal is filtered by: ##EQU22## where is is stator current, is0 is a filtered pseudo stator current, and G is greater than 0.
3. The method of claim 2 wherein said voltage signal is filtered by: ##EQU23## where u is stator voltage, u0 is a filtered pseudo stator voltage, and G is greater than 0.
4. The method of claim 3 wherein rotor speed is estimated as a solution of equations below: ##EQU24## .
5. A method of estimating rotor speed of a multi-phase induction motor, comprising estimating rotor speed as a function of filtered stator current and voltage signals and first and second order derivatives of the filtered stator current signal and first order derivative of the filtered stator voltage signal, wherein said current signal is filtered by: ##EQU25## where is is stator current, is0 is a filtered pseudo stator current, and G is greater than 0 and wherein said voltage signal is filtered by: ##EQU26## where u is stator voltage, u0 is a filtered pseudo stator voltage, and G is greater than 0.
6. A rotor speed estimator, comprising:
(a) a current observer that filters measured stator current signals to provide pseudo current signals thereof,
(b) a voltage observer that filters measured stator voltage signals to provide pseudo voltage signals thereof,
(c) a rotor speed observer that estimates rotor speed as a function of the pseudo stator current and voltage signals and first and second order derivatives of the pseudo current signal and first order derivative of the pseudo voltage signal.
7. The estimator of claim 6 including a second rotor speed observer for a singular point of motor dynamics.
8. The estimator of claim 6 wherein said current observer filters said measured stator current signal by: ##EQU27## where is is stator current, is0 is a filtered pseudo stator current, and G is greater than 0.
9. The method of claim 6 wherein said voltage observer filters said measured voltage signal by: ##EQU28## where u is stator voltage, u0 is a filtered pseudo stator voltage, and G is greater than 0.
10. The method of claim 6 wherein rotor speed is estimated as a solution of: ##EQU29## .
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Cited By (51)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6166514A (en) * 1997-03-19 2000-12-26 Hitachi, Ltd. Apparatus and method for controlling induction motor
US6198248B1 (en) * 1998-11-04 2001-03-06 Alstom Enterprise Sa Method of controlling a rotary electrical machine, a servo-control system for implementing the method, and a rotary machine fitted with such a system
US6316904B1 (en) 2000-06-27 2001-11-13 Ford Global Technologies, Inc. Speed and rotor time constant estimation for torque control of an induction motor
US6326762B1 (en) * 1999-08-18 2001-12-04 WEG AUTOMACãO LTDA Method of braking a vector controlled induction machine, control device for carrying out the method and storage medium
US6407531B1 (en) * 2001-01-09 2002-06-18 Delphi Technologies, Inc. Method and system for controlling a synchronous machine over full operating range
US6429648B1 (en) * 2000-05-26 2002-08-06 Mitsubishi Denki Kabushiki Kaisha Current detecting device and current detecting method
GB2377509A (en) * 2001-03-29 2003-01-15 Ford Global Tech Inc Sensorless control system for induction motor
US6509711B1 (en) * 2000-04-26 2003-01-21 Ford Global Technologies, Inc. Digital rotor flux observer
WO2003031918A1 (en) * 2001-10-09 2003-04-17 Abb Ab Device, system and method for on-line monitoring of flow quantities
US6566840B1 (en) 2002-02-11 2003-05-20 Ford Global Technologies, Inc. Method and system for self-calibration of an induction machine drive
GB2385219A (en) * 2002-01-30 2003-08-13 Ford Global Tech Inc A method for controlling torque in a rotational sensorless induction motor control system
EP1345315A1 (en) * 2000-12-18 2003-09-17 Kabushiki Kaisha Yaskawa Denki Method for correcting estimate of speed of induction motor and its device
US6646412B2 (en) 2002-02-11 2003-11-11 Ford Global Technologies, Llc Method and system for controlling torque in a powertrain that includes an induction motor
US6650082B1 (en) * 2000-07-27 2003-11-18 Texas Instruments Incorporated Fast rotor position detection apparatus and method for disk drive motor at standstill
US20040007995A1 (en) * 2002-07-11 2004-01-15 Visteon Global Technologies, Inc. Vector control system for permanent magnet sychronous machines using an open-loop parameter observer
US6703809B2 (en) * 2002-03-05 2004-03-09 Rockwell Automation Technologies, Inc. Flux position identifier using high frequency injection with the presence of a rich harmonic spectrum in a responding signal
US20040070363A1 (en) * 2002-10-10 2004-04-15 Bardsley David J. Integrated induction starter/generator system with hybrid control for high speed generation and idle speed smoothing
KR100428505B1 (en) * 2001-07-06 2004-04-28 삼성전자주식회사 Method of speed speed and flux estimation for induction motor
US6762580B1 (en) 2001-08-16 2004-07-13 Lexmark International, Inc. Electric motor velocity controller
US6838778B1 (en) 2002-05-24 2005-01-04 Hamilton Sundstrand Corporation Integrated starter generator drive having selective torque converter and constant speed transmission for aircraft having a constant frequency electrical system
US6838779B1 (en) * 2002-06-24 2005-01-04 Hamilton Sundstrand Corporation Aircraft starter generator for variable frequency (vf) electrical system
US20050057208A1 (en) * 2003-09-17 2005-03-17 Seibel Brian J. Method and apparatus to regulate loads
US6965212B1 (en) 2004-11-30 2005-11-15 Honeywell International Inc. Method and apparatus for field weakening control in an AC motor drive system
US20050253550A1 (en) * 2004-05-14 2005-11-17 Takayoshi Matsuo Leakage inductance saturation compensation for a slip control technique of a motor drive
US20060066275A1 (en) * 2004-09-29 2006-03-30 Thunes Jerry D Method and apparatus to regulate torque provided to loads
US7023166B1 (en) * 1999-06-24 2006-04-04 Albert Kohen Method for torque control of an induction motor using a voltage controller
US20070063665A1 (en) * 2005-09-20 2007-03-22 Takayoshi Matsuo Method and apparatus for monitoring motor status using induced motor voltage
US20070216337A1 (en) * 2006-03-14 2007-09-20 Rockwell Automation Technologies, Inc. Motor speed estimation system and method using hybrid model reference adaptive system
US20070224074A1 (en) * 2006-03-27 2007-09-27 Daido Metal Company Ltd. Method of manufacturing a clad material of bronze alloy and steel
US20080061728A1 (en) * 2006-09-11 2008-03-13 Sanyo Electric Co., Ltd. Motor control device and current detecting unit
US7560895B2 (en) 2007-03-16 2009-07-14 Azure Dynamics, Inc. Indirect rotor resistance estimation system and method
EP2192413A1 (en) 2008-12-01 2010-06-02 ABB Oy Method and apparatus for estimating a rotation speed of an electric motor
US20110057595A1 (en) * 2009-09-08 2011-03-10 Ron Flanary Method of Controlling a Motor
US20110056708A1 (en) * 2009-09-08 2011-03-10 Jonathan Gamble Fire-Extinguishing System with Servo Motor-Driven Foam Pump
US20110056707A1 (en) * 2009-09-08 2011-03-10 Jonathan Gamble Fire-Extinguishing System and Method for Operating Servo Motor-Driven Foam Pump
US20110093167A1 (en) * 2005-12-23 2011-04-21 Connel Brett Williams Power Steering Systems
US20110291596A1 (en) * 2010-05-26 2011-12-01 Haihui Lu Method and Apparatus for Controlling Motor Torque
US20120038311A1 (en) * 2010-08-16 2012-02-16 Baumuller Nurnberg Gmbh Apparatus And Method For Rotating-Sensorless Identification Of Mechanical Parameters Of A Three-Phase Asynchronous Motor
US8183810B2 (en) 2009-09-08 2012-05-22 Hoffman Enclosures, Inc. Method of operating a motor
CN102780444A (en) * 2012-08-06 2012-11-14 无锡艾柯威科技有限公司 Motor stator flux linkage estimating method
US20130082630A1 (en) * 2011-10-04 2013-04-04 Melexis Technologies Nv Determining rotor position in sensorless switched reluctance motors
US20130093375A1 (en) * 2011-07-28 2013-04-18 Vestas Wind Systems A/S Method of position sensorless control of an electrical machine
US20130187573A1 (en) * 2010-09-30 2013-07-25 Thk Co., Ltd. Control apparatus for linear motor, and linear motor apparatus
US20140340019A1 (en) * 2013-05-20 2014-11-20 Lsis Co., Ltd. Inverter and method of controlling same
US20150037169A1 (en) * 2012-03-19 2015-02-05 CoMoCo. B.V. Determination method and a control method for a fluid displacement device, controller and system
US20150288310A1 (en) * 2014-04-02 2015-10-08 Canrig Drilling Technology Ltd. Method for Controlling Torque in Permanent Magnet Motor Drives
US20160190961A1 (en) * 2014-12-30 2016-06-30 Tesla Motors, Inc. Electric motor using multiple reference frames for flux angle
US9520821B1 (en) * 2015-08-19 2016-12-13 Nidec Motor Corporation System and method for optimizing flux regulation in electric motors
US9729099B1 (en) 2016-05-19 2017-08-08 Nxp Usa, Inc. Sensorless control of AC induction motor method and apparatus
US20180227448A1 (en) * 2017-02-09 2018-08-09 Canon Kabushiki Kaisha Sheet conveyance apparatus and image forming apparatus
US10439531B2 (en) * 2016-11-29 2019-10-08 Canon Kabushiki Kaisha Sheet conveying apparatus and image forming apparatus

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5162727A (en) * 1989-12-02 1992-11-10 Abb Stromberg Drives Oy Method and apparatus of determining the stator flux estimate of an electric machine
US5463301A (en) * 1993-11-12 1995-10-31 Samsung Aerospace Industries, Ltd. Vector controlling method and apparatus for induction motor
US5510689A (en) * 1990-10-01 1996-04-23 Wisconsin Alumni Research Foundation Air gap flux measurement using stator third harmonic voltage
US5541488A (en) * 1994-04-11 1996-07-30 Sundstrand Corporation Method and apparatus for controlling induction motors
US5559419A (en) * 1993-12-22 1996-09-24 Wisconsin Alumni Research Foundation Method and apparatus for transducerless flux estimation in drives for induction machines
US5565752A (en) * 1993-12-22 1996-10-15 Wisconsin Alumni Research Foundation Method and apparatus for transducerless position and velocity estimation in drives for AC machines
US5729113A (en) * 1997-01-21 1998-03-17 General Electric Company Sensorless rotor velocity estimation for induction motors
US5818192A (en) * 1995-08-04 1998-10-06 The Boeing Company Starting of synchronous machine without rotor position of speed measurement

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5162727A (en) * 1989-12-02 1992-11-10 Abb Stromberg Drives Oy Method and apparatus of determining the stator flux estimate of an electric machine
US5510689A (en) * 1990-10-01 1996-04-23 Wisconsin Alumni Research Foundation Air gap flux measurement using stator third harmonic voltage
US5463301A (en) * 1993-11-12 1995-10-31 Samsung Aerospace Industries, Ltd. Vector controlling method and apparatus for induction motor
US5559419A (en) * 1993-12-22 1996-09-24 Wisconsin Alumni Research Foundation Method and apparatus for transducerless flux estimation in drives for induction machines
US5565752A (en) * 1993-12-22 1996-10-15 Wisconsin Alumni Research Foundation Method and apparatus for transducerless position and velocity estimation in drives for AC machines
US5541488A (en) * 1994-04-11 1996-07-30 Sundstrand Corporation Method and apparatus for controlling induction motors
US5818192A (en) * 1995-08-04 1998-10-06 The Boeing Company Starting of synchronous machine without rotor position of speed measurement
US5729113A (en) * 1997-01-21 1998-03-17 General Electric Company Sensorless rotor velocity estimation for induction motors

Cited By (77)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6166514A (en) * 1997-03-19 2000-12-26 Hitachi, Ltd. Apparatus and method for controlling induction motor
US6198248B1 (en) * 1998-11-04 2001-03-06 Alstom Enterprise Sa Method of controlling a rotary electrical machine, a servo-control system for implementing the method, and a rotary machine fitted with such a system
US7023166B1 (en) * 1999-06-24 2006-04-04 Albert Kohen Method for torque control of an induction motor using a voltage controller
US6326762B1 (en) * 1999-08-18 2001-12-04 WEG AUTOMACãO LTDA Method of braking a vector controlled induction machine, control device for carrying out the method and storage medium
US6509711B1 (en) * 2000-04-26 2003-01-21 Ford Global Technologies, Inc. Digital rotor flux observer
US6429648B1 (en) * 2000-05-26 2002-08-06 Mitsubishi Denki Kabushiki Kaisha Current detecting device and current detecting method
US6316904B1 (en) 2000-06-27 2001-11-13 Ford Global Technologies, Inc. Speed and rotor time constant estimation for torque control of an induction motor
US6650082B1 (en) * 2000-07-27 2003-11-18 Texas Instruments Incorporated Fast rotor position detection apparatus and method for disk drive motor at standstill
EP1345315A1 (en) * 2000-12-18 2003-09-17 Kabushiki Kaisha Yaskawa Denki Method for correcting estimate of speed of induction motor and its device
EP1345315A4 (en) * 2000-12-18 2014-05-21 Yaskawa Denki Seisakusho Kk Method for correcting estimate of speed of induction motor and its device
US6407531B1 (en) * 2001-01-09 2002-06-18 Delphi Technologies, Inc. Method and system for controlling a synchronous machine over full operating range
GB2377509B (en) * 2001-03-29 2004-12-29 Ford Global Tech Inc Sensorless control system for induction motor
GB2377509A (en) * 2001-03-29 2003-01-15 Ford Global Tech Inc Sensorless control system for induction motor
KR100428505B1 (en) * 2001-07-06 2004-04-28 삼성전자주식회사 Method of speed speed and flux estimation for induction motor
US6762580B1 (en) 2001-08-16 2004-07-13 Lexmark International, Inc. Electric motor velocity controller
US6918307B2 (en) 2001-10-09 2005-07-19 Abb Ab Device, system and method for on-line monitoring of flow quantities
US20050031443A1 (en) * 2001-10-09 2005-02-10 Bertil Ohlsson Device, system and method for on-line monitoring of flow quantities
WO2003031918A1 (en) * 2001-10-09 2003-04-17 Abb Ab Device, system and method for on-line monitoring of flow quantities
US6683428B2 (en) 2002-01-30 2004-01-27 Ford Global Technologies, Llc Method for controlling torque in a rotational sensorless induction motor control system with speed and rotor flux estimation
GB2385219A (en) * 2002-01-30 2003-08-13 Ford Global Tech Inc A method for controlling torque in a rotational sensorless induction motor control system
US6646412B2 (en) 2002-02-11 2003-11-11 Ford Global Technologies, Llc Method and system for controlling torque in a powertrain that includes an induction motor
US6566840B1 (en) 2002-02-11 2003-05-20 Ford Global Technologies, Inc. Method and system for self-calibration of an induction machine drive
US6703809B2 (en) * 2002-03-05 2004-03-09 Rockwell Automation Technologies, Inc. Flux position identifier using high frequency injection with the presence of a rich harmonic spectrum in a responding signal
US6838778B1 (en) 2002-05-24 2005-01-04 Hamilton Sundstrand Corporation Integrated starter generator drive having selective torque converter and constant speed transmission for aircraft having a constant frequency electrical system
US6838779B1 (en) * 2002-06-24 2005-01-04 Hamilton Sundstrand Corporation Aircraft starter generator for variable frequency (vf) electrical system
US20040007995A1 (en) * 2002-07-11 2004-01-15 Visteon Global Technologies, Inc. Vector control system for permanent magnet sychronous machines using an open-loop parameter observer
US20040070363A1 (en) * 2002-10-10 2004-04-15 Bardsley David J. Integrated induction starter/generator system with hybrid control for high speed generation and idle speed smoothing
US6982533B2 (en) * 2003-09-17 2006-01-03 Rockwell Automation Technologies, Inc. Method and apparatus to regulate loads
US20050057208A1 (en) * 2003-09-17 2005-03-17 Seibel Brian J. Method and apparatus to regulate loads
US20050253550A1 (en) * 2004-05-14 2005-11-17 Takayoshi Matsuo Leakage inductance saturation compensation for a slip control technique of a motor drive
US7187155B2 (en) * 2004-05-14 2007-03-06 Rockwell Automation Technologies, Inc. Leakage inductance saturation compensation for a slip control technique of a motor drive
US20060066275A1 (en) * 2004-09-29 2006-03-30 Thunes Jerry D Method and apparatus to regulate torque provided to loads
US7095209B2 (en) * 2004-09-29 2006-08-22 Rockwell Automation Technologies, Inc. Method and apparatus to regulate torque provided to loads
US6965212B1 (en) 2004-11-30 2005-11-15 Honeywell International Inc. Method and apparatus for field weakening control in an AC motor drive system
US7279865B2 (en) * 2005-09-20 2007-10-09 Rockwell Automation Technologies, Inc. Method and apparatus for monitoring motor status using induced motor voltage
US20070063665A1 (en) * 2005-09-20 2007-03-22 Takayoshi Matsuo Method and apparatus for monitoring motor status using induced motor voltage
US20110093167A1 (en) * 2005-12-23 2011-04-21 Connel Brett Williams Power Steering Systems
US20070216337A1 (en) * 2006-03-14 2007-09-20 Rockwell Automation Technologies, Inc. Motor speed estimation system and method using hybrid model reference adaptive system
US7298105B1 (en) * 2006-03-14 2007-11-20 Rockwell Automation Technologies, Inc. Motor speed estimation system and method using hybrid model reference adaptive system
US20070224074A1 (en) * 2006-03-27 2007-09-27 Daido Metal Company Ltd. Method of manufacturing a clad material of bronze alloy and steel
US20080061728A1 (en) * 2006-09-11 2008-03-13 Sanyo Electric Co., Ltd. Motor control device and current detecting unit
US7728537B2 (en) * 2006-09-11 2010-06-01 Sanyo Electric Co., Ltd. Motor control device and current detecting unit
US7560895B2 (en) 2007-03-16 2009-07-14 Azure Dynamics, Inc. Indirect rotor resistance estimation system and method
US20100134064A1 (en) * 2008-12-01 2010-06-03 Abb Oy Method and apparatus for estimating a rotation speed of an electric motor
CN101750512B (en) * 2008-12-01 2013-10-30 Abb公司 Method and apparatus for estimating rotation speed of electric motor
US8405344B2 (en) * 2008-12-01 2013-03-26 Abb Oy Method and apparatus for estimating a rotation speed of an electric motor
EP2192413A1 (en) 2008-12-01 2010-06-02 ABB Oy Method and apparatus for estimating a rotation speed of an electric motor
US8183810B2 (en) 2009-09-08 2012-05-22 Hoffman Enclosures, Inc. Method of operating a motor
US8164293B2 (en) 2009-09-08 2012-04-24 Hoffman Enclosures, Inc. Method of controlling a motor
US8297369B2 (en) 2009-09-08 2012-10-30 Sta-Rite Industries, Llc Fire-extinguishing system with servo motor-driven foam pump
US20110056707A1 (en) * 2009-09-08 2011-03-10 Jonathan Gamble Fire-Extinguishing System and Method for Operating Servo Motor-Driven Foam Pump
US20110056708A1 (en) * 2009-09-08 2011-03-10 Jonathan Gamble Fire-Extinguishing System with Servo Motor-Driven Foam Pump
US20110057595A1 (en) * 2009-09-08 2011-03-10 Ron Flanary Method of Controlling a Motor
US20110291596A1 (en) * 2010-05-26 2011-12-01 Haihui Lu Method and Apparatus for Controlling Motor Torque
US8519662B2 (en) * 2010-05-26 2013-08-27 Rockwell Technologies, Inc. Method and apparatus for controlling motor torque
US8604745B2 (en) * 2010-08-16 2013-12-10 Baumuller Nurnberg Gmbh Apparatus and method for rotating-sensorless identification of mechanical parameters of a three-phase asynchronous motor
US20120038311A1 (en) * 2010-08-16 2012-02-16 Baumuller Nurnberg Gmbh Apparatus And Method For Rotating-Sensorless Identification Of Mechanical Parameters Of A Three-Phase Asynchronous Motor
US8970142B2 (en) * 2010-09-30 2015-03-03 Thk Co., Ltd. Control apparatus for linear motor, and linear motor apparatus
US20130187573A1 (en) * 2010-09-30 2013-07-25 Thk Co., Ltd. Control apparatus for linear motor, and linear motor apparatus
US20130093375A1 (en) * 2011-07-28 2013-04-18 Vestas Wind Systems A/S Method of position sensorless control of an electrical machine
US8884566B2 (en) * 2011-07-28 2014-11-11 Vestas Wind Systems A/S Method of position sensorless control of an electrical machine
US20130082630A1 (en) * 2011-10-04 2013-04-04 Melexis Technologies Nv Determining rotor position in sensorless switched reluctance motors
US9059651B2 (en) * 2011-10-04 2015-06-16 Melexis Technologies Nv Determining rotor position in sensorless switched reluctance motors
US20150037169A1 (en) * 2012-03-19 2015-02-05 CoMoCo. B.V. Determination method and a control method for a fluid displacement device, controller and system
CN102780444A (en) * 2012-08-06 2012-11-14 无锡艾柯威科技有限公司 Motor stator flux linkage estimating method
US9413280B2 (en) * 2013-05-20 2016-08-09 Lsis Co., Ltd. Inverter and method of controlling same
US20140340019A1 (en) * 2013-05-20 2014-11-20 Lsis Co., Ltd. Inverter and method of controlling same
US20150288310A1 (en) * 2014-04-02 2015-10-08 Canrig Drilling Technology Ltd. Method for Controlling Torque in Permanent Magnet Motor Drives
US9722522B2 (en) * 2014-04-02 2017-08-01 Canrig Drilling Technology Ltd. Method for controlling torque in permanent magnet motor drives
US20160190961A1 (en) * 2014-12-30 2016-06-30 Tesla Motors, Inc. Electric motor using multiple reference frames for flux angle
US9509240B2 (en) * 2014-12-30 2016-11-29 Tesla Motors, Inc. Electric motor using multiple reference frames for flux angle
US9520821B1 (en) * 2015-08-19 2016-12-13 Nidec Motor Corporation System and method for optimizing flux regulation in electric motors
US9729099B1 (en) 2016-05-19 2017-08-08 Nxp Usa, Inc. Sensorless control of AC induction motor method and apparatus
US10439531B2 (en) * 2016-11-29 2019-10-08 Canon Kabushiki Kaisha Sheet conveying apparatus and image forming apparatus
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